1. Field of the Invention
The present invention relates generally to wireless communication devices and associated networks, and more particularly to mobile stations communicating data within wireless communication networks such as General Packet Radio Service (GPRS) networks.
2. Description of the Related Art
A wireless communication device, such as a mobile station, establishes a packet data protocol (PDP) context with a General Packet Radio service (GPRS) wireless network through a GPRS attach. The GPRS attach makes the wireless device known to the network by sending identification and routing area information. The wireless device goes from an idle state to a ready state if the GPRS attach is successful. During a GPRS attach procedure, encryption parameters are established between the wireless device and the GPRS network. When the data connection is reset correctly, both the wireless device and the GPRS network reset their respective encryption parameters.
During an out-of-coverage condition with the network, however, the wireless device may be powered off or reset. This will cause the wireless device to reset its data connection parameters (e.g. its encryption parameter), but the wireless network will fail to disconnect since the wireless device is out-of-coverage. When the wireless device re-enters network coverage and sends a GPRS attach in attempt to re-establish a PDP context, the encryption parameter of the wireless device is out-of-sync with the encryption parameter of the GPRS network. Thus, no encrypted data can be transmitted between the device and the network successfully, including PDP context requests.
Accordingly, there is a resulting need for methods and apparatus for reestablishing a data connection that overcomes the deficiencies of the prior art.